zfs_context: move empty __init/__exit macros to zfs_context_os

These are actually implementable in userspace, and may belong elsewhere
when/if that happens. This is convenient for the moment.

Sponsored-by: https://despairlabs.com/sponsor/
Signed-off-by: Rob Norris <robn@despairlabs.com>

Author: robn

include/sys/zfs_context.h

@@ -134,12 +134,6 @@ extern "C" {
 typedef off_t loff_t;
 #endif
 
-/*
- * Kernel modules
- */
-#define	__init
-#define	__exit
-
 #endif  /* _KERNEL || _STANDALONE */
 
 #ifdef __cplusplus

lib/libspl/include/sys/zfs_context_os.h

@@ -53,4 +53,10 @@ extern int handle_tunable_option(const char *, boolean_t);
 extern void kernel_init(int mode);
 extern void kernel_fini(void);
 
+/*
+ * Kernel modules
+ */
+#define	__init
+#define	__exit
+
 #endif